Plotter for drafting



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M. E. THOMPSON.

PLOTTER FOR DRAFTING. No. 335,853. @Patented Feb. 9, 1886..

WITNESSES ATTORNEYS.

TTNTTJED STaTns PATENT @Trreia.

MILTON E. THOMPSON, OF BABTOYV, FLOR-IDA. r

PLQTTER FOR DRAFTING.

SPECIFICATION forming part of Letters Patent No. 335,853, dated February 9, 1886.

Application filed September 14, 1885. Serial No. 177,098. (Model) T ctZZ whom it may concern.-

Be it known that I, MILTON E. THOMPSON, of Bartow, in the county of Polk and State of Florida, have invented a new and Improved Drafting-Instrument, of which the following is a full, clear, and exact description.

The object of my invention is to provide a new and improved drafting-instrument for making perspectives and like drawings,which instrument can also be used for drawing parallel lines, &c.

Reference is to be had to the accompanying drawings, forming part of this specification, in which a plan View of my improved draft- 1 ing-instrnment is shown.

The invention consists in a special combination of straight -edges, pivots, and connecting-rods, as will be fully set forth hereinafter, and then pointed out in the claims.

A, B, and O are three straight-edges or rules, of which the latter-which is between the two former-is provided with a longitudinal slot, C. The right-hand ends of the rules A and B are connected with the right-hand end of the rule G by the connecting-rods D, pivoted by the pivots a Z) 0. Two rods, E, each having a longitudinal slot, E, are pivoted to the left-hand ends of the rules A B O, and a pivot, F, is passed through the slot 0 and the slots E of the bars E. Rods G are pivoted to the right-hand end of the rule 0 by the pivot c, and pivots g on the left-hand ends of the rods G are passed through the slots E of the bars E. Bods H are pivoted on the ends of the rules A and B by the pi vots a b, and their left-hand ends are united by a pivot, 7L, passed through the slot 0 of the rule G. A rule, J, is hinged to the upper edge of the rule A, and to the rule J a curved slotted arm, K, is secured, through the slot of which a binding-screw, L, is passed into the rule A. The several pivots are binding-screws for locking the several pieces in place in relation to each other. The top edges of the rules A B converge to the same point in whatever position they may be. The rule B is secured parallel with the edge of the drawingboard, and the rule A is moved toward or from the same to get the desired lines. The

5o distances from the pivot F to the pivots e 'pivots a b, a parallel rule is formed.

must always be greater than the distances from the pivot c to the pivots a b. When the distances from the pivot F to the pivots e are equal to the distances from the pivot c to the The edge of the rule A converges to the vanishing point, but not lines parallel with said edge. To remedy this, I have provided the additional rule J, which can be so adjusted that its continuation extends to vanishing point. The radius of the distance from the vanishing point to the pivot F can easily be adjusted by moving or adjusting the pivot F a greater or less distance from the left-hand end of the rule G.

Having thus described my invention, what I. claim as new, and desire to secure by Letters Patent, is

1. The combination, with the rules A B C, of the rods 1), connecting the rules A B 0, 7c and the adjustable rods E, connecting rules A B C at the opposite ends, substantially as shown and described.

2. The combination, with the rules A B (J, of the rods 1), pivoted to the rules A B G, and the slotted rods E, eonnectii'ig the rules A B O at the opposite ends, substantially as herein shown and described.

3. The combination, with the rules A B (l, the latter having the slot 0, of the rods 1), 3O connecting the rules A B O, the slotted rods E, pivoted to the rules A B, and the pivot F, passed through the slots C and E in the rule 0 and rods E, respectively, substantially as herein shown and described.

L. The combination, with the rules A B O. the latter having the longitudinal slot G, of the rods D, connecting the rules A B O, the slotted rods E, pivot F, the rods G, pivoted to the rule 0, and the pivots g on the ends of 0 the rods G, passed through the slots E, substantially as herein shown and described.

5. The combination, with the rules A B O, the latter having the slot 0, of the rods D, connecting the rules A B O, the slotted rods E, 9 5 pivoted to the rules A B, the pivot F, the rods H, pivoted to the ends of the rules A B, and the pivot h, passed through the ends of the rods 11 and the slot (3, substantially as herein shown and described.

6. The combination, with the rules A B G, the rule J, and the binding-screw L, substanthe latter having the slot 0, of the rods D, E,

tially as herein shown and described. G, and H, substantially as herein shown and MILTON F THOMPSON described. 5 7. The combination, with the rules AB 0, XVitnesses:

of the rods D E, connecting them, the rule J, C. E. REED, hinged on the rule A, the slotted arm K on 1 1). W. REED. 

